25.12.2 Performance Schema Setup Tables

The setup tables provide information about the current
instrumentation and enable the monitoring configuration to be
changed. For this reason, some columns in these tables can be
changed if you have the UPDATE
privilege.

The use of tables rather than individual variables for setup
information provides a high degree of flexibility in modifying
Performance Schema configuration. For example, you can use a
single statement with standard SQL syntax to make multiple
simultaneous configuration changes.